Airplane shock absorber



Aug. 6, 1929. F. R. wEYMoUTH AIRPLANE SHOCK ABSORBER Filed April 4, 1927 @5% a/M4 J.' Euro1 ym,

Patented dans d, 190ml Laterna application april t,

ribis invention relates to slioelr absorbers and particularly to slioclr absorbers tor tbe landing cliasses of airplanes. u

The primary object et tbe intention is tbe provision ot a shock absorber especially adapted lor aircratt use, Wbicli incorporates both a liquid damping means tor absorbing tbe initial major sboclr ot landing, and ren allient device tor resiliently supporting tbe load, The resilient device preterably corre prises a series ot rings baring trictionally ter-engaging surfaces which are adapted to ,e one on tbe other, as tbe triction rings .telescope together when a load is applied @non rings may be in tlie :torni ot endless ds presenting sliglitly tapered Ltriction surfaces otnl a character nbicb, place tbe bands under radial tensional and conipres sional strains, Wlien 'tbe series ot rings is compressed in the direction oit its airis.

tls preferably constructed tbe snoclr ab sorber is in tbe 'torni ol an elongated casing composed ot a loner part and an upper part telescopieally received therein and ot smaller diameter tlian tlie loner part9 tbe lower part :iorrning a housing tor tlie series oit :tricticn rings and also a container or receptacle tor a quantity od damping liopiid rrliicli snbstan tially lilla tbe lower part oit tlie casina.. lliis damping liquid tinds its 'way tliroagli a sinall oritlce9 past tlie piston on tbe letter end el tbe upper part ot the casing when the ini-- tial sboclr el landing is absorbed, and tbe subsequent action oil tbe ring springs per n'iits tbe resilient support ot tbe load.,

el "liirtlier object ol tlie invention is tbe provision ot this type ol airplane slioelr ab sorber as an elongated ineinber with ineans at either end tor attachment to tbe :luselage and to tbe landing gear aille? so tbat tlie entire slioelr absorber casing inay serre as a strat to interconnect tbe aille to tbe luselage.,

llliirtlier objects and advantages ot rny in rention will nacre tally appear tbe following description oil tbe prelerred ernbodunent as illustrated in die dran/ings? in nbicli l a central section tlirongli tbe sliocli; absorben and t El is a perspective nien et tbe application et tlie elioclr absorber to an airplane ltelerring inore particularly to tbe dranings by relerence nnrnerals9 tbe airplane sliown in lllig. 2l designated generally l9 is provided anitli treo landing nlieels 2, eacli ol which is supported nitli an anle raenaber d i Y f raar. aerea na laaste eacli ol "ic/bieb is binged at its inner end to tbe lower central portion ot the fuselage.. The arles 3 Wbicli support tbe `wheels are tornied ol a "il shape so that the Wheels are braced in a llore and alt direction in a rigid inanner. 'lllie Wheels 2 are permitted to yield vertically by ineans ont tbe slioclr absorber casing l Wbicli acts as a strut between tlie connection 5 at tbe luselage and tlie connection at tlie lower end el tbe easing Wbere it is attached to the apen ol the ld el tbe aale 3.

@The slioclr absorber is torined oli an npper easing ineinber 69 torined as an elongated cylinder closed at its upper end and telescopically engaging tbe npper end et tbe lan/er casing ineinber l'. 'llie lower casing rneinber l is permanently connected at its lower end to an end plate 8 in tir/bieb is 'lastened 'tbe spherical end connection a, .lt Will be nnderstood that tbe spherical end connection or ball. 9 torrns part ot tbe ball and soclret joint 'which is prorided'to interconnect tbe casing to the landing Wbeel aille.. llie upper end ot casing member 'l is tbreaded into a casting l0, and a loclr nut ll belde tbese two parts assembled. 'llbe casting lllis provided with a thread l2 Wliicli receives tbe gland nut i8 by ineans ot which tbe packing lll is beld in place. lliis paclring lorins a llnid tiglit connection so tliat tbe lower end 'out tbe upper casing n niayinoye up and donn witliin tbe gland nut i3, Wliicli is comparatively long so tliat tbe joint between tbe two members il and l inayjwitbstand bending strains.

rifbe lower end el tbe upper casing ineinber f3 is provided with internal threads l5 which receive threads provided in tlie cylindrical extension le ol tbe plunger or piston ll rllie plunger or piston l'l is tlnis lastened secnrely to tbe casing inenaber d and is prerented troni becoming loose diie to rotation by tbe Cotter pin lll. il sinall passage lil is provided in the side ol the cylindrical nienaber t6 as stron/n and a passage 20 closed by a screw nieinber c(ll provided in tbe casting lll tlirongli Wliicli oil inay be supplied to tbe casing Jlllie ripper end tbe casing nienrber 6 is permanently tastened to an end cap a2 nliicb rigidly liolds tbe ball 23 Wliicli is adapted to cooperate Witb tbe socket at tbe point ti ribera tbe casing is attached to the luselage.

'llbe lower casing rneinber l supporta a series ot' endless or integrally closed rings tliere being a nnnaber ot inner rings all and lill 'lli

lill

lllll gether by a follower 26 which is shown in its normal position against the bushingy 27 which is fixed within the upper end of the casing member 7. The follower 26 is moved downwardly to compress the rings together, by the piston member 17 which engages the follower after the piston has traveled through a small distance from the position shown in Fig. 1. The lower casing member 7 is full of a suitable damping fluid, preferably a liquid 28 such as oil, and this lower casing member 7 is of. substantially larger diameter than the upper casing member 6 which, however, is of greater length than the lower casing member. The piston 17 may therefore travel downwardly Within the casing member 7 so as to engage the follower 26 and compress the rings to vtheir utmost before the upper casing member 7 is completely filled with the damping oil. This oil finds its way through a suitable leak around or through the piston 17 and for this purpose a small orifice 29 is provided in the center of the piston. This orifice is of such size that the initial major shock of landing is absorbed without rebound mainly in the squash of thedampingliquid as the oil flows through the'restricted orifice into the lupper casing member 6. The initial shocks of landing which are even greater than usual, are absorbed first by the squash of4 the damping li uid and then by the friction ing springs w ich are compressed as previously mentioned. The sprlngs yieldingly .support the load without appreciable rebound, as the rebound is largely absorbed by the frictionv between the rings and by the restriction of the opening 29 provided for the flow of damping 1i uid which retards down-How as well as upow of liquid. After the initial shock of landing has been absorbedv the airplanel is resiliently supported by means of the friction rings or springs which absorb the minor shocks as the airv plane runs along the ground.

' ing means for absorbing the initial shock of landing without rebound and a device for resiliently supportingthe load effective only after the initial shock of landing has been absorbed.

2. In a combination in an airplane shock absorber,`a liquid damping means for absorb- C ing the initial shock of landing and a resilient frictional device for resilientl supporting the load and effective to resiliently support the load only after initial shock of landing has been absorbed by said liquid damping means.

3. n combination in an airplane shock absorber, a casing, a liquid damping means therein for absorbing the major initial shoclr of landing without rebound, and a resilient device therein for resiliently supporting the load, and effective to resiliently support the load only after the major initial shock of landing has been absorbed by said liquid damping means.

4. ln combination in an airplane shoclc absorber, a casing, a liquid damping means therein for absorbing the major initial shock of landing, and a resilient device therein for resiliently supporting the load, said device comprising a series of closed rinfrs having complementary similarly taperedD friction surfaces, such as to permit compression and rebound of the spring.

5. A shock absorber for airplanes comprising an elongated casing member formed of upper and lower telescoping sections, a q uantity of damping fluid in the lower sect1on,a piston member at the lower end of the upper section, abypass orifice for said damping Huid, and a series of inter-engaging complementary friction members within the lower section adapted to be resiliently compressed b said piston member upon application of tlie load.

i. A. shock absorber for airplanes comprlsing an elongated upper casing member, a lower casing member normally located below the level of said upper member, a quantity o dampin liquid in said lower member, a series o rin springs having interengaging tapered frictional surfaces within said lower member, a member fixed to the lower end of said upper casing' member adapted to act on said springs to compresa the same upon application of the load, and

series of riilg springs'.

a bypass to permit a limited flow of liquid from the lower to the upper casing member.

7. A shock absorber for airplanes comprising an elongated upper casing member,

alower casing member normally located be-f low the level of said upper member, a-quantity of dam-pingV liquid within said lower member, a series of ring springs having inter-engaging tapered frictional surfaces within said lower member, a follower iixed to the lower end of said upper casing member adapted to act on said springs to compress the same upon application of the load, and a bypass to permit a limited llow of liquid from the lower to the upper casing member, the upper casing member being of substantially greater length and smaller diameter than the lower casing member.

-8. A shock absorber' comprising'an elongated casingformed of an upper andalower section, auantity of damping liquid sub` stantially lling the lower section, a seriesl of ring springs having tapered inter-engaging friction surfaces within said lower section, and apiston member" normally located a Asubstantial distance from the end of the 9. A shock absorber for airplanes Vas set forth in `claim 7, said upper casing member having a joint member at its upper end adapted to be connected to the fuselage, and

spring means for resiliently restraining y.

movements of the piston; and effective only `after large degrees of movement of the pis ton within the cylinderL 12. In a device of the class described adapted to absorb the energy of exerted compressive forces, means for initially absorbing the energy of an exerted compressive force at a substantially constant rate, and additional means brought into operation when the irst means has' reached a predetermined positioning under the influence of said compressive forces for additionally absorbing energy of compressive forces.

13. In a device of the class described adapted to absorb the energy -of exerted compressive forces, means for initially absorbing the energy of'an exerted compressive i'orce without substantial rebound, and additional means brought into operation when the first meanslias reached a predetermined positioning under the influence of said compressive forces for additionally absorbing energy of succeeding compressive forces .in a resilient manner.

14; A shock absorber of the 'class dev scribed comprising liquid damping meansfor absorbing shocks, and a resilient frictional device normally immersed in the liq-l uid for resilientlysupporting a load.

v15. A shock absor er for su rting a vehicle comprising a casing, liquiifdamping means in said. casing for absorbing shocks, and a resilient spring device in said casing for resiliently supporting. the load, said liquid damping p means acting to restrict rebound of the spring device.

16. In an airplane shock absorber, a normally upright casing, liquid damping means in said; casing for absorbing shocks, and a resilient frictional spring device normally immersed in the liquid tending to resiliently support the load, said liquid damping means acting to restrict rebound of the spring device.

In testimony whereof I have hereunto set my hand this 9th day of March,-1927.

FREDERICK R. wEYMoUTH. 

